Definitely boundary violations but not sure about malpractice. Many of our doctors would not write long term scripts especially since you are on multiple benzos. We often refer the patient to the ER but they will only get a few day supply there as well.

As far as talking with other psychiatrists does she have a release...

Do you think it is possible that she is upset because initially she agreed to help you out because you were in a difficult place financially. Now you appear to have money but are helping your mother out. Has your mom actually been approved for SSI and will be getting the money. If not she may be afraid that you are going to keep incurring the debt.